It is possible that the word valleys
could mean strength.
1 But the more common understanding is that it refers to the fertile valleys of Ammon. The main accusation in this verse (Jeremiah 49:4) is that the Lord’s judgment has come against Ammon because of the nation’s pride. They trusted in her treasures, saying Who will come against me?
Ammon placed great confidence in their riches and resources to make them secure from any enemy. The reality is that Ammon was a faithless daughter
who broke her covenant with Babylon and her false sense of security would be shattered when Nebuchadnezzar sent his armies against her.
4 Why do you boast of your valleys, O faithless daughter, who trusted in her treasures, saying, ‘Who will come against me?’